Latch release contact for electric switches



Feb. 19, 1952 MlLLER 2,586,075

LATCH-RELEASE CONTACT FOR ELECTRIC SWITCHES Filed May 27, 1947 Patented Feb. 19, 1952 uNiTEoffs'rA -"iss PATENTL'T OFFICE men aELEAsii ooN'rAcrQFon ELECTRIC c SWITCHES v v EdwinAugust Miller, mantra;- Conn. x A p ication yrayzy, 1947, Serial No. 750,668

This invention relates to latch-release contacts for electric switches and more particularly to such a latch-release contactthatis accompanied by a throw-'ofi movement that'ginsures snap-acting and wiping contacts.

The objects of the invention are to provide positive locking contacts; to provide a very linear.

novel and useful combinations of movement with operating parts so arranged that there is introduced thereby a greater and more uniform contact pressure by reason of the fact that movable parts of contact operating means are consistently co-operating with, rather than against,'relative movements thereof.

Referring to the accompanying drawingjthe Figure 1 is an upright front view of the mechanism of the device in one position; Figure 2' is a similar front view as that of the Figure 1 but with movable parts in different relative positions; Figure 3 is an enlarged side view of a portion of mechanism of device showing operating lever parts in substantially upright-alignment and easing supports. for pivotal parts; Figure 4 is a plan view of a single contact member and yielding stops; Figure 5 is an upright view of a double contact member; Figure 6 is a forwardly tipped detail of the front and rear plates of a double contact member; and Figure '7 is a detail of upper extremity of operating lever partly in cross-section. v v v r With more particular reference to theaccompanying drawing, the numeral I; designatesthe base and various portions thereof. Pivotally mounted as at 2A and 3A upon the base lzare the upright relatively spacedulatch' mem'bersii and 3, each having on' theinwardlyfacing .side edge 'thereof alaterallyj extending ,nubji igor 5 and therebelow on said edge, a recess BForlg the opposite side edge of eachlatch'memberl or 3 being engageable, as at 8 or 9 with fixed stop means 8A or 9A provided by said base I- to limit one way the movement of .each latch member ,2 or 3. Also engageable with saidopposite side edge .of each: latchrmember 2:or;3 isaa spring -"-5 Claims (or. zoo ro) l liorll' supported at one end by the base I. Pivotally mounted upon the rod 12 supported by said biasefor rotation intermediate the latch members 2 and 3 is a rocker element [3 having relatively aligned arms I4 and [5, the extremity of each arm being adapted for insertion within a recessi dor I of the'spring-pressed latch member 2 or 3, the upper edge of each of said arms M and ldbeing provided with a cam surface itincreasing in elevation toward the extremity of that-arm; 'The rod 12, while pivotally movable withinthe'b ase I, has a square or angled-shaped cross-section engaging and carrying the rocker 'elenientltr Upon the opposite side of the base support F the rod l2 again assumes said angledshaiped bross-section extending rearwardly for a purpose to be explained.

The actuator lever is constructed in two normally continuous parts I! and I8, the part ll being pivotally mounted on the base I by means of the pivot I9, and the part I8 being pivotally mountem inoverlappedrelation to the part I1, upoir' th'e same pivot 19. The lever part I"! is extendedbeyond 'the pivot I9 to provide a fanshaped-izboxportion 2 0 containing and supporting e uaIIy-stifE Springs': 21 upon either side of, and

in" engagement with, that portion of the lever part-318 extendingthrough said box portion 2%, the iextremity 22" being movable .between the latches lziandi. .As illustrated by the Figure 6, theluipper portion'of the lever part [8 is provi'ded cwith a sliding pivot 23 within a slot 24 provided with. a spring 25 having its lower end engagednagainst the pivot 23in its lowest positionlwithin the slot-2 4, the upper end of the sprin'gz25 being engaged within a cap 26 having threaded relationwith the exterior surface of may be fixedly keyed to, and carried by, the rod l2 at the rear:- of the mechanism illustrated by the Figure B, the contact arm 28 or it so carried beingmovable only with the rocker element id. The contact arm -ZS carrying'contacts Si!- is thus movable between yielding stops 31A, each springpressed by; a-spring-fil having one end supported by the base I. The contact arm 29 is provided with upper and lower bores 33-34 for connecting rods 35-36 extending therethrough, said rods 3536 supporting at either end the contact supports 31-38, each carrying a pair of contacts 39-40 and 4l42, respectively, the rods 35-36 each being provided with springs 43-44 in engagement with and between supports 31- 38 and either side of the contact arm 29.

The actuator I'l-IB is shown as having upon one side a return spring HA, but if desired this spring I'IA may be omitted if the actuator l'||8 and mechanism of the device is to have main-- tained positions.

In use, assuming that the relative positionsoi the mechanism parts of the device are found to be in the position as illustrated by the Figure 4 in such manner as to not permit the downward movement of either rocker arm M or l5 upon the ordinary engagement of the roller element 21 therewith, such elevated engagement will force the snap-acting movement of such arm [4 or IE whereby the stuck or welded contacts will be broken away.

It will be further noted that the improved latch-release device above set forth produces novel and useful patentable features in structure not found in the previous art, such as the quick l with the actuator [1-18 engaged by the springl HA and showing an arm M of the rocker element l3 locked within theprecess 30f the latch member 2, the actuating lever |'ll8 may be moved to the right, thus carrying the upper lever part l8 which ordinarily will remain in strict alignment with the lever part I! as held by the springs 2|. By such movementof the actuator means ll--I8 the roller element 21 is made to travel upwardly upon the upper edge of the tilted rocker i3 until reaching the center thereof and then the roller element 2'! bears against the arm l4 against the spring 25 until the nub [8A of the swung actuator lever parts ll--|8, as one unit causes the engagement of the nub 18A with the nub 4 of the latch member 2 and moves the latch member 2 backwardly against the spring l0 thereby releasing the arm M of the rocker element l3 from within the recess 6 and suddenly throws downwardly the rocker arm 14, as illustrated by the Figure 2, and locks the arm I5 within the recess 1 of the latch member 3. This movement being a snap-acting one will also likewise operate the contact arm 28 or 29, whichever one is carried by the rear projection of the rod l2, into contactposition with relation to the yielding stops 30A, or will operate the pairs of contacts 3940v and 4I--42 carried by the yielding supports 3138, respectively, as illustrated by the Figures 4 and 5. The yieldingstop MA or the yielding supports 31-38 fully compensates, with the co-operation of the yielding movement as between the actuator parts l'll8, for all over-operating movements of the actuator means.

The actuator I'l-l8 having been operated as above described, the spring A (or manually moved actuator means) returns the actuator lever i'|-l8 and the mechanism to relative positions illustrated by the Figure 1. In this return movement, the roller element 21 travels upwardly the upper edge of the rocker l3 of the arm IS in exactly the same manner as above described with respect to the arm I4, releasing the arm [5 from within the recess 1 and locking the arm [4 within the recess 6 of the latch member 2 and breaking and making contacts with'respect to the contacts 30 or with respect to the pairs of contacts 39-40 or 4l--42 as already described.

The Figure 2 illustrates the roller element 21 as having travelled up onto the higher level of the cam surface 16 of the arm M of the rocker element l3, such elevating movement of the actuator l!l8 being required only provided that the contacts 30, or contacts 39-40 and 4I42, carried by the arms 28 or 29, respectively, stick, or have become welded, to their respective stops breaking of sticking or welded contacts by means of cam surfaces I6 included in the structure of the upper edge of both arms I4'|5 of the rocker element [3; the more constant operating pressure due to the roller 21 moving in an are comparable with that of the cam surfaces l6; and the structure of the pivotally united actuator parts I 1-48 normally held in alignment, one with the other, although relatively yieldable by means of forced movement against stiff springs 2| carried by the actuator part I! and opposingly engaging the actuator part I8.

I claim:

1. A contact latch-and-release mechanism comprising a rocker member keyed to a pivot mounting extending through a support; a contact arm keyed to said mounting upon the opposite side of said support, said arm carrying contacts for movement between spaced stops provided by said support, said contacts and stops being relatively yielding and wiped; relatively aligned oppositely extending rigid arms carried by said rocker member; cam-surfaces of convex form with which the top edge of each rocker arm is provided adjacent the free end thereof; a twopart pivotally connected lever normally held in relative alignment by opposing spring means yieldable by force applied to one of said parts, said lever extending above and pivoted to said support below said rocker member; a pair of upright spring-pressed and relatively spaced latch members pivoted to said support upon either side of said rocker member, said latch members having interfacing edge recesses to alternately'receive an arm extremity of said rocker member as tipped; laterally projecting interfacing nubs provided by latch members above said recesses; fixed stops provided by said support to limit the separating movement of said latch members; and a spring-pressed sliding pivot mounted upon the head of the upper part of said lever, said pivot carryinga roller member for travel upon the said top edge of said rocker member upon the movement of said aligned lever parts.

2. A contact latch and release mechanism comprising a rocker member keyed to one extremity of a rod pivotally mounted upon a support, said rocker being provided with oppositely extending arms; a cam-surface of convex form provided upon the upper edge extremity of each of said arms; a contact member keyed to the opposite extremity of said rod; a two-part lever having pivotal connection, one with the other and with said support, and both parts normally supported in relatively upright alignment by means ofopposing stiff springs carried by one lever part against the other part, said lever parts extending directly upward behind said rocker member,

the lower lever part serving as an actuator;= a spring-pressed roller member carried by the upper extremity of said two-part lever for travel upon said upper edge of said arms; a pair of up right spring-pressed latch members pivotally mounted upon said support upon opposite sides of said rocker member; a recess provided upon each of the interfacing edges of said latch members for alternately receiving an extremity of one of said upwardly tipped rocker arms; a lateral projection upon opposite edges of said upper lever extremity for alternate engagement with said latch members; spaced stops provided by said support to limit the movement of said contact member, whereby the normal operation of said actuator is adapted to move in relative alignment both lever parts to carry said roller member along an upwardly inclined rocker arm and to pushingly engage a projection of said lever against said spring-pressed latch member to release said rocker arm therefrom, but, upon an unyielding welded or sticking contact, a more forceful operation of said actuator makes said roller member travel up onto an inclined cam surface of one of said oppositely extending arms of said rocker member to break such contact, the said stiff springs tending to compensate any overtravel of said lower lever actuator part.

3. A switch contact latch and release mechanism comprising a rocker member keyed to one extremity of a shaft pivotally mounted upon a support, said rocker member being provided with oppositely extending arms; an elongated camsurface provided by said rocker member including said rocker arms; interfacing inclined cam surface provided by said elongated cam-surface adjacent both extremities thereof; a contact member keyed to the opposite extremity of said shaft; a two-part lever pivotally connected one to the other and to said support and normally supported in substantial alignment by means of opposing stiff springs carried by one lever part against the other part, said two-part lever extending beyond said rocker member and the lower part providing an actuator means; a downwardly spring-pressed roller member carried by the upper extremity of said two-part lever for travel upon said elongated and inclined cam-surfaces; a pair of upright spring-pressed latch members each pivotally mounted upon said support upon opposite sides of said rocker member; a recess provided by each of the interfacing edges of said latch members for alternately receiving an extremity of a rocker arm as tipped therefor; and spaced stops provided by said support to limit the pivotal movements of said contact member whereby an operation of said actuator means is adapted to move both lever parts to carry said roller member along said elongated cam-surface and on the inclined cam-surface of a rocker arm, the upper extremity of said two-part lever operatively engaging a spring-pressed latch member to release a latch recess from a rocker arm,

4. A switch contact latch and release mechanism comprising a, rocker member keyed to a pivot-mounting extending through a support; a contact member keyed to said pivot-mounting, said contact member carrying contacts for movement therewith between spaced stops provided by said support, said contacts and stops being yielding and wiped; oppositely extending rigid arms carried by said rocker member; a continuous cam-surface with which an edge of said rocker member is provided including said arms;

a projection provided by said cam-surface adjacent each of the arm extremities; interfacing oblique cam-surfaces provided by said projections; a two-part pivotally connected operating lever normally held in relative alignment by means of opposing springs each having an end held by one part of said two-part lever and an opposite end held by said other part of said lever, the pivot connecting said lever parts extending through said support, the upper one of said twopart lever extending beyond said rocker member; a pair of upright spring-pressed latch members pivoted to said support one upon either side of said rocker member; a recessed keeper provided by each of the interfacing edges of said latch members for alternate reception of one of said rocker arm extremities as tipped therefor; fixed stops provided by said support to limit the separating movements of said latch members; and a spring-pressed downwardly sliding pivot mounted within a slot provided by the head of said upper part of said two-part lever, said pivot carrying a roller member for travel over said cam-surface of said rocker member and to mount an oblique cam-surface of one of said projections to force a rocker arm to unlatched position as the two-part lever is operated to engage its said head portion thereof against said spring-pressed latch member to release said keeper from said rocker arm while the other of said arm extremities engages against another spring-pressed latch member and slides within the keeper thereof.

5. A contact lock-and-release mechanism comprising a rocker member keyed to a pivot mounting extending through a support; a contact member carried by said pivot mounting upon the opposite side of said support, said contact member carrying contacts for movement between spaced stops provided by said support; relatively aligned oppositely extending arms carried by said rocker member; cam surfaces with which the top surface of each rocker arm is provided; a two-part pivotally connected lever normally held in relative alignment by opposing spring means yieldable to force applied to one of said parts, said lever being pivoted to said support below said rocker member; a pair of upright spring-pressed and relatively spaced latch members pivoted to said support one upon either side of said rocker member, said latch members having interfacing edge recesses to alternately receive an arm extremity of a tipped rocker member; and a springpressed sliding pivot mounted upon the upper part of said lever, said pivot carrying a member for travel upon the said top edge of each rocker arm upon the actuated movement of said aligned lever parts.

EDWIN AUGUST MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,270,951 Jeffrey Jan. 27, 1942 2,280,262 Purat Apr. 21, 1942 2,294,559 Jeffrey Sept. 1, 1942 2,369,964 Goff Feb. 20, 1945 2,390,365 Goff Dec. 4, 1945 

